This invention is generally directed to bisazo compositions and to processes for the preparation thereof. More specifically, the present invention is directed to bisazo photogenerating pigments prepared from thioxanthenediamine dioxide, and imaging members thereof. In one embodiment of the present invention, there are provided layered photoconductive imaging members with improved xerographic properties, inclusive of high charge acceptance, low dark decay, high photosensitivity, including photosensitivity in the wavelength regions of from about 400 to about 700 nanometers, enabling their selection for electrophotographic, especially xerographic, imaging systems and LED printers, which are usually sensitive to wavelengths of from about 600 to about 680 nanometers. In one embodiment of the invention of the present application, there are provided imaging members with photoconductive layers comprised of the bisazo pigments illustrated herein, and charge or hole transport layers, especially those comprised of aryl amines, which members are sensitive to light in the wavelength region of from about 400 to about 700 nanometers. The resulting members are responsive to visible light, and red illumination originating from LED printing apparatuses. The photoresponsive imaging members of the present invention can also, for example, contain situated between a photogenerating layer and a hole transporting layer, or situated between a photogenerating layer and a supporting substrate with a charge transport layer in contact with the photogenerating layer, a photoconductive composition comprised of the bisazo photogenerating pigments illustrated herein.
Imaging members with certain bisazo pigments are known, reference for example U.S. Pat. No. 3,898,084, which discloses, for example, the azo pigment Chlorodiane Blue in a photoconductive imaging member. Further, there are disclosed in the prior art layered photoresponsive devices, including those comprised of separate generating layers, and transport layers as described in U.S. Pat. No. 4,265,990, the disclosure of which is totally incorporated herein by reference; and overcoated photoresponsive materials containing a hole injecting layer overcoated with a hole transport layer, followed by an overcoating of a photogenerating layer; and a top coating of an insulating organic resin, reference U.S. Pat. No. 4,251,612. Examples of photogenerating layers disclosed in these patents include trigonal selenium and phthalocyanines, while examples of transport layers include certain diamines as mentioned therein.
In a patentability search report the following U.S. patents were listed: U.S. Pat. No. 4,299,896 which discloses imaging members with a photosensitive layer selected from the disazo pigments of the formulas illustrated, for example, in the Abstract, and in column 2; U.S. Pat. No. 4,314,015 wherein the disazo pigments for the imaging member are of the formula as illustrated in the Abstract, for example, and column 2; U.S. Pat. No. 4,666,810 wherein the azo pigments are illustrated in column 2 for example; and U.S. Pat. No. 4,797,337 wherein the disazo photogenerating pigment is of the formula as illustrated in the abstract, for example, which disazos may contain a SO.sub.2 group.
U.S. Pat. No. 3,574,181 discloses disazo compounds useful as coloring agents. Composite electrophotographic photosensitive materials containing various azo compounds are disclosed in U.S. Pat. No. 4,618,672, wherein bisazo compounds particularly suitable for use in the charge generating layer of a layered electrophotographic photoconductor are illustrated. Similarly, an article by M. Hashimoto entitled "Electrophotographic Sensitivity of Fluorenone Bisazo Pigments," Electrophotography, Vol. 25, No. 3 (1986), discloses disazo compounds as charge generating materials in electrophotographic layered photoreceptors. Further, Japanese Patent Kokai No. 54-20736 discloses disazo pigments as constituents in electrophotographic processes. Japanese Patent 58-177955 also discloses many disazo compounds suitable for use in the photosensitive layer of an electrophotographic device.
U.S. Pat. No. 4,713,307, the disclosure of which is hereby totally incorporated herein by reference, also discloses photoconductive imaging members containing a supporting substrate, certain azo pigments as photogenerating materials, and a hole transport layer that preferably contains an aryl diamine compound dispersed in an inactive resinous binder.
U.S. Pat. No. 4,797,337, the disclosure of which is totally incorporated herein by reference, discloses a photoconductive imaging member comprising a supporting substrate, a hole transport layer, and a photogenerating layer comprising specific disazo compounds.
Additional references illustrating layered organic electrophotographic photoconductor elements with azo, bisazo, and related compounds include U.S. Pat. No. 4,390,611, U.S. Pat. No. 4,551,404, U.S. Pat. No. 4,596,754, Japanese Patent 60-64354, U.S. Pat. No. 4,400,455, U.S. Pat. No. 4,390,608, U.S. Pat. No. 4,327,168, U.S. Pat. No. 4,299,896, U.S. Pat. No. 4,314,015, U.S. Pat. No. 4,486,522, U.S. Pat. No. 4,486,519, U.S. Pat. No. 4,555,667, U.S. Pat. No. 4,440,845, U.S. Pat. No. 4,486,800, U.S. Pat. No. 4,309,611, U.S. Pat. No. 4,418,133, U.S. Pat. No. 4,293,628, U.S. Pat. No. 4,427,753, U.S. Pat. No. 4,495,264, U.S. Pat. No. 4,359,513, U.S. Pat. No. 3,898,084, U.S. Pat. No. 4,830,944, U.S. Pat. No. 4,820,602, and Japanese Patent Publication 60-111247.
In U.S. Pat. No. 4,833,052, the disclosure of which is totally incorporated herein by reference there are illustrated certain bisazo photoconductive imaging members. Examples of bisazo compounds disclosed in this patent include those of the formulas as illustrated in column 4, such as 4,4'-bis(1"-azo-2"-hydroxy-3"-naphthanilide)-1,1'-dianthraquinonylamine.
U.S. Pat. No. 4,755,443 discloses a photoreceptor for electrophotography which comprises a charge carrier generating material and charge transport material wherein one charge generating material is a metal phthalocyanine or a metal-free phthalocyanine. The layer containing the generator material also contains an organic amine. Other carrier generating substances can be used in combination with the phthalocyanine generator material, including azo pigments, anthraquinone dyes, perylene dyes, polycyclic quinone dyes, and methine stearate pigments.
U.S. Pat. No. 4,424,266 discloses an electrophotographic photosensitive element having a conductive support and a photosensitive layer comprising a carrier generating phase layer containing a carrier generating material selected from the group consisting of perylene dyes, polycyclic quinones, and azo dyes, and a carrier transporting phase layer containing a hydrazone carrier transporting material. The carrier generator materials can be used either singly or in combination.
U.S. Pat. No. 4,882,254, the disclosure of which is totally incorporated herein by reference, discloses a layered photoresponsive imaging member which comprises a supporting substrate, a photogenerator layer comprising a mixture of first and second pigments, and an aryl amine hole transport layer. The mixture of pigments is selected from perylenes and phthalocyanines, polycyclic quinones and phthalocyanines, or perinones and phthalocyanines.
Japanese Patent Publication J01-198-763 discloses an electrophotographic photoreceptor containing a bisazo series compound in a photosensitive layer formed on a conductive support. A charge transport material is used with the bisazo pigment as a charge generation material, such as 2,4,7-trinitrofluorenone, tetracyanoquinodimethane, carbazole, triarylalkane derivatives, phenylenediamine derivatives, hydrazone compounds, or stilbene derivatives.
Photoresponsive imaging members containing perinone and perylene compounds are also known. For example, European Patent Publication 0040402, DE3019326, filed May 21, 1980, discloses the use of N,N'-disubstituted perylene-3,4,9,10-tetracarboxyldiimide pigments as photoconductive substances. Specifically, there are disclosed in this publication evaporated N,N'-bis(3-methoxypropyl)perylene-3,4,9,10-tetracarboxyldiimide dual layered negatively charged photoreceptors with improved spectral response in the wavelength region of 400 to 700 nanometers. A similar disclosure is contained in Ernst Gunther Schlosser, Journal of Applied Photographic Engineering, Vol. 4, No. 3, page 118 (1978). Further, U.S. Pat. No. 3,871,882 discloses photoconductive substances comprising specific perylene-3,4,9,10-tetracarboxylic acid derivative dyestuffs. According to the teachings of this patent, the photoconductive layer is preferably formed by vapor depositing the dyestuff in a vacuum. This patent discloses dual layer photoreceptors with perylene-3,4,9,10-tetracarboxylic acid diimide derivatives, which have spectral response in the wavelength region of from 400 to 600 nanometers. Additionally, U.S. Pat. No. 3,879,200 discloses imaging members with perinones. Furthermore, layered imaging members with imidazole thiazinoperinone photogenerators and related components are illustrated in U.S. Pat. No. 4,517,270 and in Japanese Laid Open Publications 59-58433/84 and 59-59692/84.
U.S. Pat. No. 4,808,506, the disclosure of which is totally incorporated herein by reference, discloses a layered photoresponsive imaging member which comprises a supporting substrate, an imidazole perinone comprising components with a mixture of cis and trans isomers of a specific formula, including trans indanthrene Brilliant Orange, cis indanthrene Bordeauxs Red, bis-(4,5-dimethyl)benzimidazole perinone and bis-2,3-naphthimidazole perinone, and an aryl amine hole transport layer.
U.S. Pat. No. 4,587,189, the disclosure of which is totally incorporated herein by reference, discloses a photoresponsive imaging member comprising a supporting substrate, a vacuum evaporated photogenerator layer which comprises a perylene pigment.
Imaging members with phthalocyanine materials are also known as disclosed in, for example, U.S. Pat. No. 3,594,163, U.S. Pat. No. 3,657,272, U.S. Pat. No. 3,816,118, U.S. Pat. No. 3,862,127, U.S. Pat. No. 3,903,107, U.S. Pat. No. 3,927,026, U.S. Pat. No. 3,932,180, U.S. Pat. No. 3,932,454, U.S. Pat. No. 4,031,109, U.S. Pat. No. 4,098,795, and U.S. Pat. No. Re. 27,117, the disclosures of each of which are totally incorporated herein by reference.
In U.S. Pat. No. 4,886,722, there is disclosed a photoconductive imaging member comprised of a supporting substrate, a hole transport layer, and a photogenerating layer comprising the unsymmetrical squaraines of the formula illustrated in claim 1; and in U.S. Pat. No. 4,833,052 there is illustrated a photoconductive imaging member comprised of a supporting substrate, a photogenerating layer comprised of a bisazo compound of the formula illustrated in claim 1, and a charge transport layer. The disclosures of each of these patents are totally incorporated herein by reference.